diff -Nru linux-2.5.74-uc0/fs/inode.c linux-2.5.x/fs/inode.c --- linux-2.5.74-uc0/fs/inode.c 2003-07-02 22:57:36.000000000 +0200 +++ linux-2.5.x/fs/inode.c 2003-07-03 09:37:22.000000000 +0200 @@ -145,6 +145,12 @@ mapping->dirtied_when = 0; mapping->assoc_mapping = NULL; mapping->backing_dev_info = &default_backing_dev_info; + +#ifndef CONFIG_MMU + mapping->i_mmap_block = NULL; + mapping->i_mmap_cnt = 0; +#endif /* !CONFIG_MMU */ + if (sb->s_bdev) mapping->backing_dev_info = sb->s_bdev->bd_inode->i_mapping->backing_dev_info; memset(&inode->u, 0, sizeof(inode->u)); @@ -183,11 +189,13 @@ sema_init(&inode->i_sem, 1); INIT_RADIX_TREE(&inode->i_data.page_tree, GFP_ATOMIC); spin_lock_init(&inode->i_data.page_lock); - init_MUTEX(&inode->i_data.i_shared_sem); INIT_LIST_HEAD(&inode->i_data.private_list); spin_lock_init(&inode->i_data.private_lock); +#ifdef CONFIG_MMU INIT_LIST_HEAD(&inode->i_data.i_mmap); INIT_LIST_HEAD(&inode->i_data.i_mmap_shared); + init_MUTEX(&inode->i_data.i_shared_sem); +#endif /* CONFIG_MMU */ spin_lock_init(&inode->i_lock); } diff -Nru linux-2.5.74-uc0/fs/locks.c linux-2.5.x/fs/locks.c --- linux-2.5.74-uc0/fs/locks.c 2003-07-02 22:56:06.000000000 +0200 +++ linux-2.5.x/fs/locks.c 2003-07-03 09:37:22.000000000 +0200 @@ -1423,6 +1423,7 @@ inode = filp->f_dentry->d_inode; +#ifdef CONFIG_MMU /* Don't allow mandatory locks on files that may be memory mapped * and shared. */ @@ -1435,6 +1436,7 @@ goto out; } } +#endif /* CONFIG_MMU */ error = flock_to_posix_lock(filp, file_lock, &flock); if (error) @@ -1561,6 +1563,7 @@ inode = filp->f_dentry->d_inode; +#ifdef CONFIG_MMU /* Don't allow mandatory locks on files that may be memory mapped * and shared. */ @@ -1573,6 +1576,7 @@ goto out; } } +#endif /* CONFIG_MMU */ error = flock64_to_posix_lock(filp, file_lock, &flock); if (error) diff -Nru linux-2.5.74-uc0/include/asm-m68knommu/mmu.h linux-2.5.x/include/asm-m68knommu/mmu.h --- linux-2.5.74-uc0/include/asm-m68knommu/mmu.h 2003-07-02 22:51:46.000000000 +0200 +++ linux-2.5.x/include/asm-m68knommu/mmu.h 2003-07-03 09:37:22.000000000 +0200 @@ -4,9 +4,10 @@ /* Copyright (C) 2002, David McCullough */ struct mm_rblock_struct { - int size; - int refcount; - void *kblock; + int size; + int refcount; + struct file *file; + void *kblock; }; struct mm_tblock_struct { diff -Nru linux-2.5.74-uc0/include/linux/fs.h linux-2.5.x/include/linux/fs.h --- linux-2.5.74-uc0/include/linux/fs.h 2003-07-02 22:43:46.000000000 +0200 +++ linux-2.5.x/include/linux/fs.h 2003-07-03 09:37:22.000000000 +0200 @@ -320,9 +320,14 @@ struct list_head io_pages; /* being prepared for I/O */ unsigned long nrpages; /* number of total pages */ struct address_space_operations *a_ops; /* methods */ +#ifdef CONFIG_MMU struct list_head i_mmap; /* list of private mappings */ struct list_head i_mmap_shared; /* list of shared mappings */ struct semaphore i_shared_sem; /* protect both above lists */ +#else /* !CONFIG_MMU */ + char * i_mmap_block; /* Pointer to memory buffer for mmapped file */ + int i_mmap_cnt; /* Track use count of i_mmap_block (FIXME: shall we use atomic_t?) */ +#endif /* !CONFIG_MMU */ unsigned long dirtied_when; /* jiffies of first page dirtying */ int gfp_mask; /* how to allocate the pages */ struct backing_dev_info *backing_dev_info; /* device readahead, etc */ diff -Nru linux-2.5.74-uc0/mm/filemap.c linux-2.5.x/mm/filemap.c --- linux-2.5.74-uc0/mm/filemap.c 2003-07-02 22:45:11.000000000 +0200 +++ linux-2.5.x/mm/filemap.c 2003-07-03 09:37:22.000000000 +0200 @@ -40,6 +40,9 @@ #include #include +/* Turn on verbose debug messages for mmap related stuff */ +#undef DEBUG_MMAP + /* * Shared mappings implemented 30.11.1994. It's not fully working yet, * though. @@ -580,12 +583,14 @@ if (!PageUptodate(page)) goto page_not_up_to_date; page_ok: +#ifdef CONFIG_MMU /* If users can be writing to this page using arbitrary * virtual addresses, take care about potential aliasing * before reading the page on the kernel side. */ if (!list_empty(&mapping->i_mmap_shared)) flush_dcache_page(page); +#endif /* CONFIG_MMU */ /* * Mark the page accessed if we read the beginning. @@ -1262,6 +1267,56 @@ return 0; } +#else /* !CONFIG_MMU */ + +int generic_file_mmap(struct file * file, struct vm_area_struct * vma) +{ + struct address_space *mapping = file->f_dentry->d_inode->i_mapping; + size_t error; + mm_segment_t old_fs; + size_t len = vma->vm_end - vma->vm_start; + + if (++mapping->i_mmap_cnt == 1) + { +#ifdef DEBUG_MMAP + printk("generic_file_mmap(): allocating %u bytes for inode #%ld\n", + len, mapping->host->i_ino); +#endif + if (!(mapping->i_mmap_block = kmalloc(len, GFP_KERNEL))) + { + --mapping->i_mmap_cnt; + return -ENOMEM; + } + } +#ifdef DEBUG_MMAP + else + printk("mmap: reusing allocated block for inode #%ld (i_mmap_cnt = %d)\n", + mapping->host->i_ino, mapping->i_mmap_cnt); +#endif + + old_fs = get_fs(); + set_fs(KERNEL_DS); + error = file->f_op->read(file, mapping->i_mmap_block, len, &file->f_pos); + set_fs(old_fs); + + if (error < 0) { + if (--mapping->i_mmap_cnt == 0) + { + kfree(mapping->i_mmap_block); + mapping->i_mmap_block = NULL; + } + return error; + } + + /* Clear rest of mapped block */ + if (error < len) + memset(mapping->i_mmap_block + error, 0, len - error); + + vma->vm_start = (unsigned long)mapping->i_mmap_block; + return 0; +} +#endif /* !CONFIG_MMU */ + /* * This is for filesystems which do not implement ->writepage. */ @@ -1271,16 +1326,6 @@ return -EINVAL; return generic_file_mmap(file, vma); } -#else -int generic_file_mmap(struct file * file, struct vm_area_struct * vma) -{ - return -ENOSYS; -} -int generic_file_readonly_mmap(struct file * file, struct vm_area_struct * vma) -{ - return -ENOSYS; -} -#endif /* CONFIG_MMU */ static inline struct page *__read_cache_page(struct address_space *mapping, unsigned long index, diff -Nru linux-2.5.74-uc0/mm/nommu.c linux-2.5.x/mm/nommu.c --- linux-2.5.74-uc0/mm/nommu.c 2003-07-03 08:39:17.000000000 +0200 +++ linux-2.5.x/mm/nommu.c 2003-07-03 10:24:12.000000000 +0200 @@ -17,13 +17,18 @@ #include #include #include -#include +#include #include #include #include #include +/* Define to enable debug output for mm */ +#undef DEBUG +#undef DEBUG_TBLOCK +#undef WARN_ON_SLACK /* 64 */ + void *high_memory; struct page *mem_map = NULL; unsigned long max_mapnr; @@ -250,9 +255,9 @@ #undef _trans } -#ifdef DEBUG static void show_process_blocks(void) { +#ifdef DEBUG_TBLOCK struct mm_tblock_struct *tblock; printk("Process blocks %d:", current->pid); @@ -263,8 +268,110 @@ printk(" (%d @%p #%d)", kobjsize(tblock->rblock->kblock), tblock->rblock->kblock, tblock->rblock->refcount); printk(tblock->next ? " ->" : ".\n"); } +#endif /* DEBUG_TBLOCK */ +} + +static struct mm_tblock_struct *create_tblock(struct mm_struct *mm, void *kblock, size_t size) +{ + struct mm_tblock_struct *tblock; + + if (!(tblock = (struct mm_tblock_struct *) + kmalloc(sizeof(struct mm_tblock_struct), GFP_KERNEL))) + goto out; + + if (!(tblock->rblock = (struct mm_rblock_struct *) + kmalloc(sizeof(struct mm_rblock_struct), GFP_KERNEL))) + goto out; + + if (!kblock) { + if (!(kblock = kmalloc(size, GFP_KERNEL))) + goto out; + + memset(kblock, '\0', size); + + realalloc += kobjsize(kblock); + askedalloc += size; + } + + /* Init rblock */ + tblock->rblock->refcount = 1; + tblock->rblock->file = NULL; + tblock->rblock->kblock = kblock; + tblock->rblock->size = size; + +#ifdef WARN_ON_SLACK + if ((size + WARN_ON_SLACK) <= kobjsize(kblock)) + printk("Allocation of %u bytes from process %d has %u bytes of slack\n", + size, current->pid, kobjsize(kblock) - size); +#endif + + realalloc += kobjsize(tblock); + askedalloc += sizeof(struct mm_tblock_struct); + + realalloc += kobjsize(tblock->rblock); + askedalloc += sizeof(struct mm_rblock_struct); + + /* Link tblock into mm list */ + tblock->next = current->mm->context.tblock.next; + current->mm->context.tblock.next = tblock; + + return tblock; + +out: + printk("Allocation of %u bytes failed (pid=%d)\n", size, current->pid); + show_free_areas(); + if (tblock) { + kfree(tblock->rblock); + kfree(tblock); + } + + return NULL; +} + +void delete_tblock(struct mm_tblock_struct *tblock, struct mm_tblock_struct *prev) +{ + if (tblock->rblock) { + if (!--tblock->rblock->refcount) { + struct file *file; + + if ((file = tblock->rblock->file)) { + struct address_space *mapping; + + mapping = file->f_dentry->d_inode->i_mapping; + +#ifdef DEBUG + printk("delete_tblock(): releasing file with f_count %d, i_mmap_cnt %d, (inode #%ld)\n", + file->f_count.counter, mapping->i_mmap_cnt, mapping->host->i_ino); +#endif + if (--mapping->i_mmap_cnt == 0) { +#ifdef DEBUG + printk("delete_tblock(): freeing mmapped block @%p (inode #%ld).\n", + mapping->i_mmap_block, mapping->host->i_ino); +#endif + kfree(mapping->i_mmap_block); + mapping->i_mmap_block = NULL; + } + + fput(file); + } + else if (tblock->rblock->kblock) { + realalloc -= kobjsize(tblock->rblock->kblock); + askedalloc -= tblock->rblock->size; + kfree(tblock->rblock->kblock); + } + + realalloc -= kobjsize(tblock->rblock); + askedalloc -= sizeof(struct mm_rblock_struct); + kfree(tblock->rblock); + } + } + + /* Unlink tblock from mm list */ + prev->next = tblock->next; + realalloc -= kobjsize(tblock); + askedalloc -= sizeof(struct mm_tblock_struct); + kfree(tblock); } -#endif /* DEBUG */ unsigned long do_mmap_pgoff( struct file * file, @@ -274,7 +381,6 @@ unsigned long flags, unsigned long pgoff) { - void * result; struct mm_tblock_struct * tblock; unsigned int vm_flags; @@ -348,95 +454,42 @@ or do something truly complicated. */ if (file->f_op->mmap) { + get_file(file); error = file->f_op->mmap(file, &vma); - #ifdef DEBUG printk("f_op->mmap() returned %d/%lx\n", error, vma.vm_start); #endif - if (!error) - return vma.vm_start; - else if (error != -ENOSYS) + if (error) + { + fput(file); return error; - } else - return -ENODEV; /* No mapping operations defined */ - - /* An ENOSYS error indicates that mmap isn't possible (as opposed to - tried but failed) so we'll fall through to the copy. */ - } - - tblock = (struct mm_tblock_struct *) - kmalloc(sizeof(struct mm_tblock_struct), GFP_KERNEL); - if (!tblock) { - printk("Allocation of tblock for %lu byte allocation from process %d failed\n", len, current->pid); - show_free_areas(); - return -ENOMEM; - } + } - tblock->rblock = (struct mm_rblock_struct *) - kmalloc(sizeof(struct mm_rblock_struct), GFP_KERNEL); + if (!(tblock = create_tblock(current->mm, (void *)vma.vm_start, vma.vm_end - vma.vm_start))) + { + fput(file); + return -ENOMEM; + } - if (!tblock->rblock) { - printk("Allocation of rblock for %lu byte allocation from process %d failed\n", len, current->pid); - show_free_areas(); - kfree(tblock); - return -ENOMEM; - } + tblock->rblock->file = file; - result = kmalloc(len, GFP_KERNEL); - if (!result) { - printk("Allocation of length %lu from process %d failed\n", len, - current->pid); - show_free_areas(); - kfree(tblock->rblock); - kfree(tblock); - return -ENOMEM; + } else + return -ENODEV; /* No mapping operations defined */ } - - tblock->rblock->refcount = 1; - tblock->rblock->kblock = result; - tblock->rblock->size = len; - - realalloc += kobjsize(result); - askedalloc += len; - -#ifdef WARN_ON_SLACK - if ((len+WARN_ON_SLACK) <= kobjsize(result)) - printk("Allocation of %lu bytes from process %d has %lu bytes of slack\n", len, current->pid, kobjsize(result)-len); -#endif - - if (file) { - int error; - mm_segment_t old_fs = get_fs(); - set_fs(KERNEL_DS); - error = file->f_op->read(file, (char *) result, len, &file->f_pos); - set_fs(old_fs); - if (error < 0) { - kfree(result); - kfree(tblock->rblock); - kfree(tblock); - return error; - } - if (error < len) - memset(result+error, '\0', len-error); - } else { - memset(result, '\0', len); + else + { + /* Handle anonymous mapping */ + if (!(tblock = create_tblock(current->mm, NULL, len))) + return -ENOMEM; } - realalloc += kobjsize(tblock); - askedalloc += sizeof(struct mm_tblock_struct); - - realalloc += kobjsize(tblock->rblock); - askedalloc += sizeof(struct mm_rblock_struct); - - tblock->next = current->mm->context.tblock.next; - current->mm->context.tblock.next = tblock; - #ifdef DEBUG printk("do_mmap:\n"); show_process_blocks(); -#endif +#endif - return (unsigned long)result; + /* Return addr of mmapped memory block */ + return (unsigned long) tblock->rblock->kblock; } int do_munmap(struct mm_struct * mm, unsigned long addr, size_t len) @@ -466,27 +519,9 @@ current->pid, current->comm, (void*)addr); return -EINVAL; } - if (tblock->rblock) { - if (!--tblock->rblock->refcount) { - if (tblock->rblock->kblock) { - realalloc -= kobjsize(tblock->rblock->kblock); - askedalloc -= tblock->rblock->size; - kfree(tblock->rblock->kblock); - } - - realalloc -= kobjsize(tblock->rblock); - askedalloc -= sizeof(struct mm_rblock_struct); - kfree(tblock->rblock); - } - } - tmp->next = tblock->next; - realalloc -= kobjsize(tblock); - askedalloc -= sizeof(struct mm_tblock_struct); - kfree(tblock); -#ifdef DEBUG + delete_tblock(tblock, tmp); show_process_blocks(); -#endif return -EINVAL; } @@ -504,28 +539,8 @@ #endif while((tmp = mm->context.tblock.next)) { - if (tmp->rblock) { - if (!--tmp->rblock->refcount) { - if (tmp->rblock->kblock) { - realalloc -= kobjsize(tmp->rblock->kblock); - askedalloc -= tmp->rblock->size; - kfree(tmp->rblock->kblock); - } - realalloc -= kobjsize(tmp->rblock); - askedalloc -= sizeof(struct mm_rblock_struct); - kfree(tmp->rblock); - } - tmp->rblock = 0; - } - mm->context.tblock.next = tmp->next; - realalloc -= kobjsize(tmp); - askedalloc -= sizeof(struct mm_tblock_struct); - kfree(tmp); + delete_tblock(mm->context.tblock.next, &mm->context.tblock); } - -#ifdef DEBUG - show_process_blocks(); -#endif } asmlinkage long sys_munmap(unsigned long addr, size_t len) diff -Nru linux-2.5.74-uc0/mm/vmscan.c linux-2.5.x/mm/vmscan.c --- linux-2.5.74-uc0/mm/vmscan.c 2003-07-02 22:41:46.000000000 +0200 +++ linux-2.5.x/mm/vmscan.c 2003-07-03 09:37:22.000000000 +0200 @@ -189,11 +189,13 @@ if (PageSwapCache(page)) return 1; +#ifdef CONFIG_MMU /* File is mmap'd by somebody. */ if (!list_empty(&mapping->i_mmap)) return 1; if (!list_empty(&mapping->i_mmap_shared)) return 1; +#endif /* CONFIG_MMU */ return 0; }